Bump node-sass from 4.13.1 to 7.0.0

Bumps [node-sass](https://github.com/sass/node-sass) from 4.13.1 to 7.0.0.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sass/node-sass/compare/v4.13.1...v7.0.0)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -40,7 +40,7 @@
     "eslint": "^6.8.0",
     "eslint-config-prettier": "^6.10.0",
     "eslint-plugin-prettier": "^3.1.2",
-    "node-sass": "^4.13.1",
+    "node-sass": "^7.0.0",
     "prettier": "^1.19.1",
     "pug": "^2.0.4",
     "pug-plain-loader": "^1.0.0",